Insulator pin



L. J. DRIGGS INSULATOR PIN May 30, 1933.

Filed Feb. 6, 1953 Larmvzo J 057663 V modification and Patented May 30, 1933 UNITED STATES PATENT OFFICE.

Lo E zo ,J. DBIGGS, OF ALToo A,.PENNsYLvANIA, Ass'IG oR ro FRANK F. WINTERS, or WILLIAMSPORT, PENNSYLVANIA INSULATOR PIN Application filed Februar 6, 1933. Serial No. 655,497.

This invention is intended to provide a novel and desirable improvementcin insulator pins such as used forelectric line-wire support or the like and constitutes an en largement upon the disclosures of my correspondingly titled pending application Ser. N 0. 570,194 filed October 21, 1931 and prior forfeited application Ser. No. 389,700 filed August 31, 1929, of which the following specification is a consolidative continuation in part. I.

--The primaryobject thereof is to produce a. hard and unbreakable pin, having a' soft orcompressible and resilient thread for the insulator engagement therewith serving to cushion thetwo apart and compensate any expansion differences therebetween, so as to eliminate the liability of insulator fracture from variations in temperature and climatic conditions. flAnother object is to originate expedient means by which the thread may be applied tothe pin with modifications according to preference or form of the same to fulfill different requirements and appliance purposes. c

With simplicity, durability and minimized expense as added desiderata in mind, the invention' will be further described with reference to the attached drawing illustrating one practical embodiment thereof in several diflt'erentforms of a common type.

In said drawing:

Fig. 1 is a side elevation of the pin partly in section and with a part shown broken away;

Fig.2 is a top plan view of the same;

Fig. 3 is a side elevation of a modification of the pin with a part shown fragmentarily;

Fig. 4 is a longitudinal section of said modification; I

, Fig. 5 is a top plan view thereof;

Fig. 6 is-a similar elevation of another Fig. 7 is a longitudinal section of the latter.

In'the illustrative embodiment, the pin standard is representedby a'bracket-arm 8, which is preferably of iron or other metal. and formed with end or side reinforcing-web flanges as shown forstrength against bendmg or snapping off under pull weight of a suspended Wire. This standard or bracket will in most instances be advantageously adapted to screwing down upon a securing base 9-as by an axial threaded bore engaging a threaded stud 9a of the latter--- which is provided in the position thereof, but may of course be otherwise afii'xed in place on the cross-arm of a line pole or other support for the same. 1

The free end ofthe standard is formed. into or provided with a circular head 10, which is axially recessed like a socket in this instance and desirably tapered somewhat toward its extremity for a well understood reason. Formed in the outer surface of this head is a groove 11 (see Fig. 1) on the line of a spiral of several convolutions there around from end toend, said groove being rather shallow in depth and the pitch of its. spiral being the same as the pitch of the thread of the insulator to be applied on the p111.

Trained in this groove around the head is a strand 12 of corded fibre material such as cotton, hemp or the like, having the great-v er portion of its body projecting from the surface of the head in the manner and form of a screw thread. In appliance to the head, the ends of the strand are of, course fastened securely against loosening and slip; page. This may be done in several different, ways later described, but it will here be noted that such fastening is made within the head below the level of the groove so asto offset the same therefrom and avoid any irregularity in the surface and continu-j ity of the strand windingsaround the head.

Said strand is contracted or shrunk into tight bindive fixture in place on the head by subjection to the action of an agent causing it to draw inwardly under effort to shorten itself and which may at the same time im part a protective or preserving coating thereto against effects of moisture and atmosphere. Various well-known liquid substances of gum or lacquer character might be used to effect this shrinkage, but the most satisfactory agent found for the purpose is 100 a compound consisting of a hydrocarbon such as formaldehyde with or without an equal part of glycerine, paraffin, benzinc and pure linseed oil in proportions of one, two, five and two parts respectively; these being dissolved and mixed together in what may be called a shellac and applied to the strand at a heated temperature. This may be done of course by dipping the head into a bath of the substance or by spraying it thereonto and it might be desirable in some instances to subject the strand to more than one coating of the compound at different temperatures. The strand so treated may be hardened somewhat, but will still retain compressible and resilient features, aided by the softening effect of the paraffin and oil.

Accordingly, the strand thus applied to the pin provides a soft or compressible and resilient thread which readily permits the insulator to be screwed down thereover and serves to cushion the insulator from the pin while yet causing it to fit tightly thereon. It also functions to compensate expansion and contraction differences between the insulator and pin so as to eliminate the liability of insulator fracture due to variations in temperature under climatic conditions, the insulator being usually of glass, porcelain or some other breakable material which expands less readily than the pin metal and so is ordinarily liable to crack and break under strains in direct contact therewith. The strand accordingly protects the one part from the other in addition to securing them together, with resultant advantage which will be readily appreciated.

As before stated, the fastening of the ends of the strand against loosening and the slippage on the head may be done in several different ways. One and the ordinarily preferred of these is illustrated in Figs. 1 and 2. In said instance, the strand ends are shown extending into slots 13 and 14 at top and bottom respectively of the head, with knots 12a therein engaging behind the same against the inner wall of the head. These slots are advantageously formed on the line of a chord across the head rather than radially of its center so as to make a less abrupt bending of the strand at the point of entry into the head and thereby give it a more gradual slope to-the beginning of the thread than would otherwise be the case.

Figs. 3, 4 and 5 illustrate a modification of this means, in which the knotted ends 124 of the strand are engaged under notched lips and 16 at the top and bottom respectively. In this instance the upper end of the strand is carried over the top edge of the head, although it might of course be countersunk in a groove across said edge.

The top lip (15) is simply a lug-like projection from the inner wall of the head, with its notch or slot formed to conveniently receive the strand, while the bottom lip (16) is similarly formed in a recess in the outer wall of the head. It will be noted that the pin standard or bracket-arm of this modification is represented in somewhat difierent form from that illustrated by the other figures in that the reinforcing-web flanges are radial to its axis instead of lateral to its sides.

Figs. 6 and 7 illustrate a distinctly different method of fastening the strand ends, there being in this instance no knotting at the ends of the same. Instead, the ends of the spiral groove (11) terminate into deeper grooves 17 running lengthwise of the head on opposite sides transversely of and in effect under said spiral groove, one of the same leading upwardly from the bottom and the other leading downwardly from the top of the head. The ends of the strand at the ends of the spiral are extended into these deeper grooves so as to underlie the intermediate portion thereof in its windings around the head and be thereby clamped firmly with the resultant pressure thereupon. In this modification, the strand contracted or shrunk in place binds the more tightly upon its ends and so fastens them as securely as the other methods where the ends are knotted and engaged within slots. p

It will be appreciated that various other modifications with changes in the form, arrangement and appliance of the parts may be made within the scope of this invention and it will therefore be understood that the same is not intended to be restricted by the appended claims to the specific embodiment or forms illustrated and hereinbefore described in detail. In this connection also, notice is drawn to the fact that the treatment of the strand. may or may not include a protective or waterproofing induction, the same being a mere'incidental feature of the invention. Such treatmentis essential to shrink it positively and permanently in place on the pin, and this should not confused with any other purpose.

Having thus described my invention, what I claim as new and desire to secure by Letters Patentof the United States is 1. An insulator pin, comprising a standard having a spiral groove in its head por tion surface and a fibre strand fitted in said groove with a fastening at opposite'ends; said strand being shrunk to a bindive fixture in place around the pin and forming a screwthread thereon.

2. An insulator pin, comprising a stand ard having a shallow groove in spiral convolution about its head portiona'nd a strand of fibre material wound therearound in lodgement Within said groove and fastened at opposite ends inside the pin; said strand being contracted to bindive fixture in place upon the pin and providing a screw-thread therefor.

3. An insulator pin, comprising a stand ard having a spiral groove around its head portion, a corded strand trained within said groove from end to end and means securing the opposite ends of the strand within the pin below the surface level of the groove; said strand being shrunk to bindive fixture in place upon the pin with a portion projecting from the groove providing a relatively soft screw-thread thereon.

4. An insulator pin, comprising a standard having a head portion with screwthread formed by a strand of fibre material contacted thereonto in a bindive affixture with anchoring against slip movement.

5. An insulator pin comprising a standard member having a head, a spiral groove in said head, a notch in the upper end of the head to which one end of said spiral groove extends with a mergence thereinto, another notch in the lower end of the head to which the other end of said groove extends and merges, and a flexible strand wound in the groove around the head and shrunk into place thereon so as to constitute a thread for the same; one end of the strand being held to and engaged in the notch at the upper end of the head and its other end being led to and engaged in the notch at the lower end of the head.

6. An insulator pin including a hollow head having a spiral groove in its outer surface, a notched lip in the upper end of the head, a strand of flexible material wound in and shrunk to the groove so as to constitute a thread for engagement of an insulator; an end of the thread being extended across the top edge of the head into said notch and knotted with an anchorage against said lip, and means securing the other end of the strand to the head.

7. An insulator pin. including an axially recessed head having a spiral groove in its outer surface; said groove having an extension in the upper end of the head communicating with its recess, a strand of material wound in and contracted to the groove with one end extending within the groove extension into said recess of the head and knotted so as to be anchored therein, and means for anchoring the other end of the strand.

8. An insulator pin comprising a stand ard having spiral and longitudinal grooves therein and a compressible strand mounted and shrunk in said grooves, the ends of said strand being in the longitudinal grooves and the intermediate portion thereof being in the spiral groove.

9. An insulator pin comprising a standard having spiral and longitudinal grooves therein, the longitudinal grooves intersecting the spiral groove, anda compressible strandmounted and shrunk in saidgrooves, the ends of said strand being in the longitudinal grooves and the intermediate por+ tion thereof being inthe spiralgroove.

1().-An insulator pin comprising a stand ard having a spiral and longitudinal grooves therein, the. longitudinal grooves intersecting the spiral groove and being of greater depth than the same, and a com-3 pressible strand mounted and contracted in said grooves, the intermediate portion of said strand being in the spiral groove and the ends thereof being in the longitudinal grooves beneath the intermediate portion.

11. An insulator pin comprising a standard having a head on its end and said head being formed with spiral and longitudinal grooves therein, and a compressible strand mounted and shrunk in said grooves; the end portions of said strand being in the longitudinal grooves and the intermediate portion thereof being in the spiral groove.

12. An insulator pin comprising a standard having a head portion and said head portion having spiral and longitudinal grooves therein, with the longitudinal grooves intersecting the spiral groove and being of greater depth-than the same, and a flexible compressible strand mounted and shrunk in said grooves, the ends of said strand being in the longitudinal grooves and the intermediate portion thereof being in the spiral groove.

13. An insulator pin comprising a standard having a tapered head formed with intersecting and endwise connected spiral and longitudinal grooves, a flexible strand trained and contracted in said grooves and constituting compressible threads for se curing an insulator to the head; the intermediate portion of said strand being in the spiral groove and the end portions thereof being in the longitudinal grooves between said intermediate portion and the head.

14. The method of producing an insulator pin which consists in forming a suitable standard with a head portion or part, grooving said head on the line of a spiral of several convolutions thereabout, training a strand of fibre material in said groove from end to end around the head, securing the ends of the strand within the head below the surface level of the groove, and causing the strand to contract in bindive fixture in place upon the head with a portion thereof projecting from the groove in the manner and form of a screw-thread.

15. The method of producing an insulator pin which consists in forming a suitable standard with a head portion or part, spirally grooving said head, training a strand of fibre material in said groove around the in the body of the head below the surface level of said groove, and subjecting the strand to a mixture of a hydrocarbon, parafiin, benzine and linseed oil so as to cause the same to contract in permanent bindive fixture in place upon the head with a, por tion thereof projecting from the groove in the manner and form of a screw-thread by which to engage an insulator on the pin.

In testimony whereof I aflix my signa- LORENZO J. DRIGGS.

- ture. 

